Measuring urban density

Sir, – The recently amended version of the article entitled “Decades of recurring housing crises remains a reality – penalising the young, rewarding the old” (David McWilliams, January 28th) includes a sentence that draws upon 2019 Eurostat data to place Dublin as the 96th most densely populated area in Europe. However, while the article in question is explicitly focused on urban population density, the above-noted Eurostat dataset is a measure of regional density via the NUTS 3 classification system. This has implications for any inferences that can be drawn from it. The 2019 Eurostat NUTS 3 dataset includes population density measurements for a total of 1,785 regions of various sizes, of which the Dublin NUTS 3 region appears in 96th position. The size of a NUTS 3 region in proportion to a city within its boundaries impacts the measured population density for that region. As an example, the Dublin NUTS 3 area matches to County Dublin and includes measurements of both urban and rural areas, thus reducing the overall density measurement significantly. The data for the Berlin NUTS 3 region, which appears in 20th position in the dataset, matches to its municipal boundaries, and is thus a more accurate measure of urban density. This raises significant challenges for making comparisons about urban density within these two NUTS 3 regions.

A closer reading of the 2019 Eurostat NUTS 3 dataset drawn upon by The Irish Times illustrates its wider limitations as an indicator of urban density. The NUTS 3 region of Freiburg im Breisgau, Germany is ranked in 97th position. Yet, the city of Freiburg is world-renowned for its urban sustainability initiatives, including density and livability. More striking again, perhaps, is the position of the Barcelona NUTS 3 region in 198th place within the Eurostat dataset. Whereas the density of Barcelona is 15,992 people per KM2, the density of the much larger Barcelona NUTS 3 region is 726.5 persons per KM2. Barcelona is often noted for its urban density credentials. As highlighted by Alasdair Rae, this includes hosting the highest density KM2 in Europe at 53,119 people per KM2 – with Paris hosting the second highest density KM2 area (52,218 per KM2) that is cited in the afore-mentioned Irish Times article.

The overall picture that emerges is that of a limitation in the use of Eurostat NUTS 3 regional data as a measure of urban density. Measuring urban density is notoriously slippery terrain. Rankings alone tell us nothing of the specifics of a particular city, whether it be the nuances of classification or the specifics of the social, economic, or other factors related to urban life. – Yours, etc,

PHILIP LAWTON,